Apex domains cannot have CNAME records.
Question and response
Question
dig philips.com._nspf.vali.email. NS
Answer
philips.com._nspf.vali.email. 5 NS ns.vali.email.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0